From d05ebe8503985f65b918945b869f295a9595ca5e Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@helsinki.at>
Date: Wed, 27 Jan 2016 23:47:38 +0100
Subject: improved VU meter


diff --git a/src/rhlibrary/player_widget.go b/src/rhlibrary/player_widget.go
index d88bbf6..8019cd9 100644
--- a/src/rhlibrary/player_widget.go
+++ b/src/rhlibrary/player_widget.go
@@ -33,31 +33,37 @@ import (
 )
 
 const (
-	meterDBFloor  float64 = 72 // -72 db is the lowest VU value
-	meterSegments float64 = 30 // meter has 30 elements
-
-	meterOffsetGreen  float64 = meterSegments - 4
-	meterOffsetOrange float64 = meterSegments - 2
-	meterOffsetRed    float64 = meterSegments - 1
+	meterDBFloor        float64 = 72 // -72 db is the lowest VU value
+	meterSegmentsGreen  float64 = 21
+	meterSegmentsOrange float64 = 3
+	meterSegmentsRed    float64 = 1
+	meterSegmentsTotal  float64 = meterSegmentsGreen + meterSegmentsOrange + meterSegmentsRed
 )
 
 var (
-	levelBarCss *gtk.CssProvider
+	meterBarCSS   *gtk.CssProvider
+	meterFrameCSS *gtk.CssProvider
 )
 
 func init() {
 	var err error
-	if levelBarCss, err = gtk.CssProviderNew(); err != nil {
+	if meterBarCSS, err = gtk.CssProviderNew(); err != nil {
 		panic(err.Error())
 	}
-	err = levelBarCss.LoadFromData(`
+	err = meterBarCSS.LoadFromData(`
 .level-bar {
   -GtkLevelBar-min-block-width: 13;
   -GtkLevelBar-min-block-height: 8;
 }
+.level-bar.trough {
+  border: 0;
+  padding: 0;
+  border-radius: 0;
+  background-image: unset;
+}
 .level-bar.fill-block.level-green {
-  border-color: #00AE00;
-  background-image: linear-gradient(to bottom, #36FF36, #00AE00);
+  border-color: #006600;
+  background-image: linear-gradient(to bottom, #36B736, #006600);
 }
 .level-bar.fill-block.level-orange {
   border-color: #AE6600;
@@ -70,6 +76,14 @@ func init() {
 	if err != nil {
 		panic(err.Error())
 	}
+
+	if meterFrameCSS, err = gtk.CssProviderNew(); err != nil {
+		panic(err.Error())
+	}
+	err = meterFrameCSS.LoadFromData(".frame { padding: 3px; }")
+	if err != nil {
+		panic(err.Error())
+	}
 }
 
 func addPlayButton(grid *gtk.Grid, p *player.PlayerChan) (err error) {
@@ -114,18 +128,40 @@ func addStopButton(grid *gtk.Grid, p *player.PlayerChan) (err error) {
 	return
 }
 
-func calcMeterLevel(valdb float64) (val float64) {
-	val = valdb + meterDBFloor
+type vuMeterLevel struct {
+	green  float64
+	orange float64
+	red    float64
+}
+
+func (lvl *vuMeterLevel) setLevel(valdb float64) {
+	val := valdb + meterDBFloor
 	if val < 0 {
 		val = 0
 	} else {
-		val = (val / meterDBFloor) * meterSegments
+		val = (val / meterDBFloor) * meterSegmentsTotal
+	}
+
+	lvl.green = val
+	lvl.orange = val - meterSegmentsGreen
+	lvl.red = lvl.orange - meterSegmentsOrange
+	if lvl.orange < 0 {
+		lvl.orange = 0
+	}
+	if lvl.red < 0 {
+		lvl.red = 0
 	}
 	return
 }
 
-func createMeterBar() (bar *gtk.LevelBar, err error) {
-	if bar, err = gtk.LevelBarNewForInterval(0, meterSegments); err != nil {
+type vuMeter struct {
+	green  *gtk.LevelBar
+	orange *gtk.LevelBar
+	red    *gtk.LevelBar
+}
+
+func createMeterBar(segments float64) (bar *gtk.LevelBar, err error) {
+	if bar, err = gtk.LevelBarNewForInterval(0, segments); err != nil {
 		return
 	}
 	bar.SetMode(gtk.LEVEL_BAR_MODE_DISCRETE)
@@ -136,41 +172,60 @@ func createMeterBar() (bar *gtk.LevelBar, err error) {
 	if sc, err = bar.GetStyleContext(); err != nil {
 		return
 	}
-	sc.AddProvider(levelBarCss, 600) // TOOD: hardcoded value
+	sc.AddProvider(meterBarCSS, 600) // TOOD: hardcoded value
+	return
+}
 
-	bar.AddOffsetValue("green", meterOffsetGreen)
-	bar.AddOffsetValue("orange", meterOffsetOrange)
-	bar.AddOffsetValue("red", meterOffsetRed)
+func newVUMeter() (meter *vuMeter, err error) {
+	meter = &vuMeter{}
+	if meter.green, err = createMeterBar(meterSegmentsGreen); err != nil {
+		return
+	}
+	if meter.orange, err = createMeterBar(meterSegmentsOrange); err != nil {
+		return
+	}
+	if meter.red, err = createMeterBar(meterSegmentsRed); err != nil {
+		return
+	}
+
+	meter.green.AddOffsetValue("green", 0)
+	meter.orange.AddOffsetValue("orange", 0)
+	meter.red.AddOffsetValue("red", 0)
 
 	return
 }
 
+func (m *vuMeter) SetValue(lvl *vuMeterLevel) {
+	m.green.SetValue(lvl.green)
+	m.orange.SetValue(lvl.orange)
+	m.red.SetValue(lvl.red)
+}
+
 func addMeter(grid *gtk.Grid, p *player.PlayerChan) (err error) {
 	var mgrid *gtk.Grid
 	if mgrid, err = gtk.GridNew(); err != nil {
 		return
 	}
-	mgrid.SetOrientation(gtk.ORIENTATION_VERTICAL)
-	mgrid.SetColumnSpacing(3)
+	mgrid.SetRowSpacing(3)
 
-	var left, right *gtk.LevelBar
-	if left, err = createMeterBar(); err != nil {
+	var left, right *vuMeter
+	if left, err = newVUMeter(); err != nil {
 		return
 	}
-	if right, err = createMeterBar(); err != nil {
+	if right, err = newVUMeter(); err != nil {
 		return
 	}
 
 	p.AddUpdateHandler(func(length time.Duration, pos time.Duration, meter player.Meter, userdata interface{}) bool {
 		glib.IdleAdd(func() {
 			ch := len(meter)
-			lval := float64(0)
-			rval := float64(0)
+			lval := &vuMeterLevel{0, 0, 0}
+			rval := &vuMeterLevel{0, 0, 0}
 			if ch >= 2 {
-				lval = calcMeterLevel(meter[0].Peak)
-				rval = calcMeterLevel(meter[1].Peak)
+				lval.setLevel(meter[0].Peak)
+				rval.setLevel(meter[1].Peak)
 			} else if ch == 1 {
-				lval = calcMeterLevel(meter[0].Peak)
+				lval.setLevel(meter[0].Peak)
 				rval = lval
 			}
 			left.SetValue(lval)
@@ -179,10 +234,25 @@ func addMeter(grid *gtk.Grid, p *player.PlayerChan) (err error) {
 		return true
 	}, nil)
 
-	mgrid.Add(left)
-	mgrid.Add(right)
+	mgrid.Attach(left.green, 1, 1, 1, 1)
+	mgrid.Attach(left.orange, 2, 1, 1, 1)
+	mgrid.Attach(left.red, 3, 1, 1, 1)
+	mgrid.Attach(right.green, 1, 2, 1, 1)
+	mgrid.Attach(right.orange, 2, 2, 1, 1)
+	mgrid.Attach(right.red, 3, 2, 1, 1)
+
+	var frame *gtk.Frame
+	if frame, err = gtk.FrameNew(""); err != nil {
+		return
+	}
+	var sc *gtk.StyleContext
+	if sc, err = frame.GetStyleContext(); err != nil {
+		return
+	}
+	sc.AddProvider(meterFrameCSS, 600) // TOOD: hardcoded value
 
-	grid.Add(mgrid)
+	frame.Add(mgrid)
+	grid.Add(frame)
 	return
 }
 
-- 
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